Patent GB-873425-A (GB)
Title: Improvements in conveyor systems
IPC: B65G47/48
Filed: 1957-07-17
Abstract: 873,425. Endless conveyers for delivering goods at predetermined positions. FREEMAN (ENGINEERS) Ltd., A., and FREEMAN, A. Oct. 15, 1958 [July 17, 1957], No. 22629/57. Class 78 (1). In a conveyer system of the kind in which work or other goods can be dispatched along an endless conveyer in association with selector devices which are composed of a plurality of selector elements, each movable between alternative positions and individually set to positions defining a combination corresponding with a particular station along the system, and in which a reader mechanism is disposed at each of these stations comprising a plurality of reader elements arranged to sense the position of the elements of a passing selector device and to respond to a device in which selector elements have a correlating setting, thereby to cause some action to be performed on the work, for example to discharge the work, each reader mechanism is so devised that it is adapted to operate additionally, at required times, as a selector - setting device. As shown, each selector device comprises a stem 7 depending from an endless conveyer chain 1 which travels in a guideway 2, the stem 7 having three superposed annular grooves in each of which is arranged a selector element comprising a piece of wire coiled around the groove, the ends of which project outwardly at an angle of 120 degrees to form fingers 8a and 8b, each of which is provided with a hook portion 9. The fingers 8a project towards the rear of the conveyer to co-operate with a combined reader and setting mechanism 5, whilst the fingers 8b project towards the front of the conveyer and co-operate with a zeroizing mechanism 6. As indicated by the arrow, Fig. 4, the fingers 8a, 8b are easily movable in a direction opposite to the direction of movement of the conveyer but only with difficulty in the direction of movement of the conveyer owing to the convolution of the wire forming the selector elements. The arrangement is such that when a finger 8a is in a projected position at right-angles to the direction of movement of the conveyer the corresponding finger 8b is retracted, that is inclined at an angle of 30 degrees to the direction of movement of the conveyer, and vice-versa. At its lower end the stem carries a pivoted U-section member 10 which is apertured so that a hook 11, on which a work-supporting member 12 may be placed, passes through it. The combined reader and setting mechanism 5 comprises three reader elements in the form of collars 17 freely rotatable about a vertical shaft 16 and each provided with a projection 18 normally positioned in engagement with a plate 40 for contact with the corresponding finger 8a, if the latter is in projected position. The projections 18 are normally maintained against the edge of the plate 40 by a depending member 22 secured to a lever 24 secured to the shaft 16 and urged by a spring 23 in a clockwise direction, as seen from above. An arm 51 on the lower end of shaft 16 normally projects into the path of the stems 7. Each selector element has a notch 19 arranged in a characteristic position around its periphery, and a pivoted plate 25 is arranged to enter these notches when all three notches are aligned. The plate 25 is secured to a shaft 26 on the lower end of which is secured an arm 27 carrying a roller 28 adapted to co-operate with an abutment surface 13 on the member 10 of each selector device. The plate 25 is urged towards the reader elements by a spring 29. Each collar 17 is also formed with a recess 20, the arrangement being such that all the recesses 20 are in line one above the other when the projections 18 are in their normal position. Three locking-pins 35, each spring-urged into a retracted position, are mounted on a plate 30 secured to a shaft 31 and are adapted when projected to enter the recesses 20. A selector plate 36 is adjustably positioned behind the plate 30 and is formed with a plurality of apertures 37. Its position is adjusted such that predetermined ones of the pins 35 pass through these apertures and are therefore retracted, while the other pins are projected. A lever 32 is secured to the lower end of the shaft 31 and extends into the path of the work supporting member 12, being biased into this position by a spring 39. The zeroizing device 6 comprises a plate 47 adapted to engage any projected finger 8b and which is secured to a vertical shaft 48 and urged by a light spring into contact with a stop 50. The plate 47 is locked in this position by a catch 46 secured to another vertical shaft 42, the lower end of which carries a lever 43 projecting into the path of the work-supporting member 12, into which position it is urged by a spring 44. In operation, when a selector device carrying a work-supporting member 12 approaches the devices 6 and 5, the lever 43 is engaged by the member 12 causing the catch 46 to be swung away from the plate 47, so that when the fingers 8b subsequently engage the plate 47 the latter is pivoted anticlockwise without altering the position of the fingers Sb. When the worksupporting member 12 subsequently engages the lever 32, the latter pivots, causing the plate 30 to be swung into the chain-line position 301 so that the pins 35 are free of the recesses 20 in the collar 17. The stem 7 of the selector device then engages the lever 51 and also the lever 24, causing the plate 25 to be swung clear of the notches 19 and member 22 to be swung away from projections 18, so that the collars 17 are now free to rotate. Those fingers 8a which are in the projected position then engage the corresponding projections 18 to rotate one or more of the collars 17 into positions depending upon the settings of the fingers 8a. If these settings correspond with the arrangement of notches 19 in the collar 17 these notches are all aligned in the plane of the plate 25, so that when the selector device releases the lever 24 plate 25 enters these notches, causing arm 27 to be swung into the position in which the roller 28 can engage an abutment face 13 of the member 10 to swing this member about its pivot, so that it discharges the work-supporting member 12 from the hook 11. When a selector device without a work - supporting member 12 approaches the devices 6, 5 the arm 43 of the zeroizing device is not engaged so that plate 47 is restrained against movement. Accordingly, when the fingers 8b engage the plate 47, they are all turned into an inclined position to project the corresponding fingers 8a. When the selector device reaches the device 5, the lever 32 is not engaged so that the projected pins 35 remain in engagement with the recesses 20 in the corresponding collars 17. Accordingly, the projections 18 of these collars engage the fingers 8a and turn them into inclined positions, while the projections 18 of the remaining collars are merely moved aside by the corresponding fingers 8a which remain in the projected position, so that the selector device is given a setting corresponding to that of the pins 35 of the setting-plate 30. Specifications 723,421, 733,419, 779,127 and 873,426 are referred to.